Humidifier



Jan. 16, 1962 E. J. SPERATH 3,016,892

HUMIDIFIER Filed June 4, 1958 5 Sheets-Sheet 1 INVENTOR ERWN J. SPERATH Jan. 16, 1962 E.. J. SPERATH HUMIDIFIER Filed June 4, 1958 FIG. 3.

5 Sheets-Sheet 2 INVENTOR ERVIN J. SPERATH W-q M M ATTORNEYS E. J. SPERATH Jan. 16, 1962 HUMIDIFIER 5 Sheets-Sheet 3 Filed June 4, 1958 FIG. 4

INVENTOR ERVIN J. SPERATH Nab-. M, M

ATTORNEYS E. J. SPERATH Jan. 16, 1962 HUMIDIF'IER 5 Sheets-Sheet 4 Filed June 4, 1958 FIG. 7.

FIGS.

INVENTOR s2 ERVIN .1. SPERATH ATTORNEYS Jan. 16, 1962 E. J. SPERATH 3,016,892

HUMIDIFIER Filed June 4, 1958 5 Sheets-Sheet 5 FIG. IO.

INVENTOR ERVIN J. SPERATH ATTORNEYS nite Zitates 3,615,892 Patented Jan. 16, 13 52 Q fiice 5,916,892 l-IUP/HDEFHER Ervin ,l'. Sperath, 723i) N. @lcott Ave, Chicago 31, llll. Filed .luee 4, 1958, Sar. No. 739,877 4 Claims. 126-113) This invention relates to improvements in humidify ng apparatus primarily intended for humidifying the air in dwellings heated by hot air furnaces, whether they be of forced air or gravity type, and whether they utilize gas, oil or other fuel. it will, of course, find utility in other buildings than dwellings, although it is primarily with respect to dwellings that the present invention has been conceived.

During the seasons when artificial heat is required for comfortable living indoors, outside air is usually relatively dry and, when heated, is of exceedingly low relative humidity. Thus, outdoor air at a temperature of 32 and having a relative humidity of 40% will, when heated to 70, have a relative humidity of only approximately 11%.

Exceedingly dry air is both unhealthful and generally discomfortable. In dry air, body moisture dries rapidly, having a cooling effect on the body and requiring a relatively high air temperature in order to maintain a comfortable atmosphere. Low humidity furthermore tends to dry the nose, throat and lung passages of an individual, as well as his skin, tending to make people subjected to such conditions more susceptible than otherwise to coughs and respiratory illnesses, and to skin diseases and discomforts.

With increased humidity, the same degree of comfort can be maintained at lower air temperatures and the air can be maintained at a more healthful and more comfortable condition With lessened fuel consumption.

With a satisfactory humidity level, dust which floats in dry air becomes moisture-laden and heavy, causing it to settle. This too tends to lessen the transmission of germ-laden dust from one person to another.

From all standpoints of comfort, health and economy, it is highly desirable to maintain a satisfactory level of humidity within a dwelling whenever possible.

Medical research and reports indicate the most health ful and satisfactory relative humidity level to be about 45% to 55%.

To maintain such a humidity level, it has been found that in the average home from 8 to 12 gallons of water daily should be evaporated into the atmosphere of the dwelling.

In most areas of human habitation, such a quantity of water, 8 to 12 gallons, will, when evaporated, have a considerable residue of non-evaporable matter, of which lime is a most common component. The deposit of lime is a most common cause of humidifier failure, since such material is most likely to be deposited on the working parts of valves and other devices in the path of vapor or hot water.

It is an object of the present invention to provide a humidifier which will readily and reliably supply any desired amount of moisture to the heated air of a dwelling.

It is a further object of the present invention to provide a humidifier which is not susceptible to functional failure because of lime deposits.

Still another object of the present invention is to prevent a high degree of lime and mineral deposits in functional element by maintaining such solutes in a nondepositing slurry or sludge which can readily be removed if it achieves an undesirable volume.

Yet another object of the present invention is to provide a humidifier which will provide a maximum amount of air moisture constantly at a minimum of care, attention and expense.

Other objects and advantages of the present invention will be readily apparent from the following description of a satisfactory embodiment, taken in connection with a form illustrated in the accompanying drawings, in which:

FIG. 1 is a front plan view of the humidifier, without the float valve tank, and with cover partially removed to show the pump, motor assembly and electrical connections;

FIG. 2 is a view partially in section taken along the line 2-2 of FIG. 1;

FIG. 3 is a view partially in section taken along the line 3-3 of FIG. 1;

FIG. 4 is a perspective view of the front of the humidifier with part of the cover broken away to disclose details of the pump and its motor;

FIG. 5 is a front view diagram showing the humidifier unit mounted in a furnace, with water connections to the saddle valve and humidifier control box;

FIG. 6 is a side view of FlG. 5 with furnace housing broken away to show the water heater element and evaporator pan placement as applied to a gas furnace;

HQ. 7 is a top plan view of the water heater element;

FIG. 8 is a diagrammatic view showing the water heater element mounted relative to the burner of an oil-fired furnace;

FlG. 9 is a perspective illustrating a modified form in which the evaporator pan is mounted externally of the furnace plenum; and

FIG. 10 is a schematic diagram showing the humidifier unit and its controls.

As illustrated in the drawings, water is supplied to a float valve Ell, of standard construction, the details of which are not shown, throu h tubing 12, which may satisfactorily be copper tubing of /4" diameter. The tubing 12 is connected to the building water supply 14 by means of a saddle valve E6. The float valve tank 18 is connected by means of a pipe Ztl to the evaporator pan 22. The

float valve lil is adjusted to maintain a water level 24 above the inlet to the pipe 2% connecting the float valve tank 18 and the evaporator pan 22. The Water is maintained at the level 24 to assure that the pump 26 is submerged. The pump 26 is an impeller type pump with large openings 23 and 3t} to permit free entrance of Water. The space 32 between the impeller 34 and the pump housing 36 should be great enough to accommodate any lime or other deposit inside the pump without operative interference.

The pump housing 36 also serves as supporting means for the motor 38 that drives the impeller 34 through the shaft ill. The motor 38 and the pump 26 are held toether by studs 42, which also support plate 44 which serves as a shield to protect the motor 38 from heat and water vapor. This permits the motor 38 and the pump 26 to be grouped as a unit.

The outlet passage 4-6, as shown, runs from the lower side of the pump 26 and, being threaded, serves also to connect the pump 26 to the evaporator pan 22.

The outlet passage 46 bear a shoulder 4 which serves two purposes: 1) to provide a spacing 50 between the pump as and the bottom of the evaporator pan 22, allowin" water to enter the pump 26 from the bottom opening fill as well as from the top opening 28; and (2) to provide a backing for the washer 52 which may desirably be made of neoprene or other synthetic rubber.

On the outside and underneath the evaporator pan 22, another washer 54, which also may desirably be made of neoprene or other synthetic rubber, is placed on the outlet tube 46, backed up by a metal washer 56. A nut 58 is then tightly secured on the outlet tube 46, thus creating a Watertight seal between the pump outlet is and the evaporator pan 22. This outlet tube 46 is then fitted with a compression fitting 55 to receive the tubing 6a which desirably may be copper tubing of its" diameter.

he tubing 6% extends into the combustion chamber 62 where it is desirably formed to the shape of a W, 64, which makes it possible to have a considerable length of tubing desirably 18" in the direct path of the fire. This tubing is the heating element. After the tubing 60 leaves the combustion chamber 62, it returns to the evaporator pan 22. The return tube 66 in the evaporator pan 22 is open at the far end 68, the open end being so adjusted as to assure it being above the water level 24 to permit an unrestricted return for the hot water to the evaporator pan 22. One end of the return tube 66 is fitted with a threaded pipe '76 to facilitate mounting it by means of washers 72 and 74 which again may desirably be made of neoprene or other synthetic rubber, a metal washer 76 and a nut 78 to form a water-tight seal to the evaporator pan 22.

This threaded pipe 70 is fitted with a compression fitting 3 to receive the tubing 60 returning from the combustion chamber 62. The significance of operation is as follows. The pump 26 forces water 24 from the evaporator pan 22 into the tube 60 through the JV-shaped portion 64 in the combustion chamber 62 where it is heated and thence returned to the evaporator pan 22 through the open end 68 of the return tube 66. The speed at which the pump 26 forces the water through the heating element 64 regulates the temperature at which the water is heated before it is returned to the evaporator pan 22. Therefore, by operating the pump with a sufiiciently high output, boiling of Water with the consequent deposit of lime can be avoided in Vii-shaped tube 64.

A removable cover plate 82 is provided on the pump 26 and evaporator 22 to protect the motor 38 from deterioration caused by heat and water vapor. This cover 82 can be removed to inspect the interior of the evaporator 22and to enable one to check the water level 24. An additional protective cover 84 is provided for the motor 38 and the electrical connections 86. A plate 38 is fastened, as by spotwelding, to the evaporator pan 22 to secure the evaporator to the furnace plenum 90. It also carries a bracket 92 to which may be attached the armored cable connector 94.

The water vapor from the evaporator pan 22 i mixed with the hot air from the furnace in the hot air plenum 9t) and is then delivered to the heated portion of the dwelling by the conventional duct system commonly used in furnace heating installations.

A rheostat 96 and relay d8 enclosed in a protective metal box 100 is provided for the control unit. The relay 93 has a coil 162 which is electrically connected to the furnace controls 104, the details of which are not shown as any standard type of control may be used. When the furnace is fired, the relay 98 operates, closing its contacts, which connects voltage from the lighting power source through the rheostat 96 to the motor 38.

The rheostat 96 is the means provided to vary the power used to drive the motor 38, and as such, varying the setting of the rheostat 96 will vary the output of the pump 26 which is driven by motor 38. In other words, the proper rheostat setting will avoid overheating of the water in tube 64. The motor 38, because of this arrangement, can never be completely shut off while the unit is operating during the fire cycle of the furnace.

The small metal control box is provided with three apertures 106, 168 and 110. Aperture 106 is for entrance of the electric power line. Aperture 108 is to accommodate the armored cable 112 leading to the motor 38. Aperture 110 is for the low voltage wire 114 from the furnace control to the relay 98.

All metal parts that have contact with the Water should preferably be of non-ferrous metal, such as brass, copper or bronze, or of stainless steel to prevent rusting. The P p 26 is an impeller type pump desirably of a size the rotating impeller within the pump housing.

rated approximately two gallons per minute. The motor may desirably be rated at horsepower.

The extreme spacing 32 between the impeller 34 and the pump housing 36, plus the large openings 28 and 30 of the pump 26, along with an unrestricted path for the water through the tubing 60, will assure trouble-free operation before lime deposits will interfere therewith or decrease efiiciency. When lime deposits are built up to an excess amount, cleaning may be required,

It will be seen that as the water 24 in the pan is evaporated, the float valve it) permits replacement of water therein equivalent to the evaporation rate, thus maintaining a substantially constant level of water in the evaporator pan 22.

By using the mechanical means of circulating water as described instead of depending upon thermo-syphon circulation, the heating element 64 can be of simple design because the danger of steam pockets in the tubing 60 is eliminated, assuring a noiseless method of heating the water for the evaporator pan 22.

Using a pump for circulation of the water also makes it possible to control the water temperature by varying the speed of the pump. Additionally, use of a pump causes any lime deposits to be kept constantly in motion, preventing the deposits from forming a solid coating on the parts or in the passageways.

An alternate method of mounting the evaporator pan 2?. outsid the furnace plenum is shown in FIG. 9. The hood 116 acts as a duct to direct the vapor from the evaporator pan 22 through an opening in the plenum 90.

From the foregoing description of the parts of a desirable embodiment of my invention, it will be seen that this invention provides a low cost, trouble-free effective and controlled means of humidifying dwellings using hot air furnace heat.

The humidifier thus described has as prominent features the forcing of water from an evaporator pan by a small impeller type pump into copper tubing of small diameter running into the combustion chamber or high heat zone of the furnace and, thence, returning to the evaporator pan. Circulation of the water prevents lime deposits or other solids from settling or forming in a solid state in any of the functionally operating portions of the humidifier.

The movement of water through the circuit is caused by the impeller pump located in the evaporator pan, the pump being driven by a small electric motor, which can be as small as A horsepower, the motor being electrically connected to the control which causes the furnace combustion chamber to be fired. When the combustion chamber becomes active, the pump motor starts and water circulation through the copper tubing commences. The speed of the pump motor is adjustable by mean of a rheostat connected in series with the motor and source of electric power.

Another novel effect brought about by the pump is that the water can never reach the boiling point which would cause the undesirable effect of pounding or knocking in the hot water circuit. Still another novel effect of mechanical circulation as compared, for example, with thermo-syphon circulation is that deposits of lime and other solutes are kept in a mud or silt state. This keeps the humidifier unit trouble-free for long periods of time, thereby greatly reducing maintenance problems and expense, The pump is so designed as to allow ample space between the impeller and the pump housing which will permit relatively large deposits of lime without affecting operation of the unit or decrease in its efficiency. The pump itself has no bearings or seals that will wear out or be afiected by heat, lime or mineral deposits. The deposits, being in silt form, will be forced out of the pump by the whirlpool action of the water caused by The water in the evaporator pan should, of course, be maintained at a level to insure that the pump is submerged.

In the embodiment above described, a simple float valve is utilized for maintenance of the desired level and, once adjusted, it will maintain substantially a constant level by adding water to the pan at a rate approximately equal to the water evaporation rate. The float valve receives its Water from the building Water supply, assuring a constant source for the humidifier.

The humidifier described is substantially automatic, that is, once the user sets the rheostat for the humidity desired and has set the float valve for the desired level, the humidity will remain at the desired point for the entire heating season with no cause for readjustment as previously stated. When the furnace is operated, drying the air in the dwelling, the humidifier is automatically placed in operation and adds water vapor to the resulting heated air to raise its relative humidity. In the apparatus described, the amount of moisture added to the hot air can be smaller, greater or equal to the drying rate of the air caused by operation of the furnace during its running cycle.

It will be seen that the humidifier of this invention is adapted to accomplish and will accomplish the objects theretofore set forth in a very desirable, economical and trouble-free manner.

Numerous modifications and variations may be made in the humidifier which is above described without departing from the important features of the invention, and it is desired that the invention be limited only by the following claims.

I claim:

1. In a hot air furnace having a hot air plenum and a combustion chamber, a humidifier comprising, in combination, an evaporator pan in the hot air plenum of said furnace, means to maintain a supply of Water in said evaporator, a tubular heating element carrying Water from said evaporator through a tortuous path through the combustion chamber of said furnace and back to said evaporator, pump means to force a sutficient flow of water through said tubular heating element and back to said evaporator pan to prevent said water from boiling and means to control the speed of said pump.

2. In a hot air furnace having a hot air plenum and a combustion chamber, a humidifier comprising, in combination, an evaporator pan in the hot air plenum of said furnace, means to maintain a substantially constant water level in said evaporator, a tubular heating element carrying water from said evaporator through a tortuous path through the combustion chamber of said furnace and back to said evaporator, an impeller pump means to impel a flow of a sufficient amount of water through said heating element and back to said evaporator to prevent boiling said water, and a rheostat to control the speed of said pump.

3. In a hot air furnace having a heated air distributor chamber and a controlled fuel supply, a humidifier comprising, in combination, an evaporator pan in the heated air distributor chamber of said furnace, float valve means to maintain a substantially constant Water level in said evaporator, a heating element adapted to carry a flow of Water from said evaporator through a tortuous path through a highly heated zone in said furnace and back to said evaporator, pump means to impel a suflicient volume of Water through said heating element to prevent boiling of said Water, and means operated by the fuel supply control for said furnace to actuate said pump.

4. A humidifier as described in claim 3 wherein the means to actuate said pump includes a relay electrically connected to the fuel supply control, said relay closing a circuit when fuel is supplied to said furnace, said circuit comprising an electric power source, a rheostat and an electric motor which is mechanically connected to drive said pump.

References Qited in the file of this patent UNITED STATES PATENTS 1,087,875 Garrecht Feb. 17, 1914 1,254,189 Bahnson Jan. 22, 1918 1,515,490 Jordan Nov. 11, 1924 1,819,423 Knowlton et al Aug. 18, 1931 1,984,866 Day Dec. 18, 1934 2,125,581 Pearce Aug. 2, 1938 2,232,347 Stuart Feb. 18, 1941 2,347,490 Legeman Apr. 25, 1944 2,860,228 Boyle et al Nov. 11, 1958 2,888,006 Martin May 26, 1959 

